Preheat oven to 350 degrees. Lightly grease a 9x13" baking dish and set aside.
Add oil to a large skillet and heat over MED HIGH heat. Add beef and cook for about 3-4 minutes, crumbling as it cooks.
Add onion, garlic and green chiles, stir, and cook another 3-4 minutes, until onions are soft and beef is cooked through.
Drain in a colander and return to skillet. Stir in black beans, half of the cilantro, and about 1/2 cup of the enchilada sauce.
To prepare the enchiladas, spread a tablespoon or two of the enchilada sauce over a tortilla, then add about 1/8th of the beef mixture down the center. Top with roughly 1/4-1/3 cup of cheese.
Roll up tortilla and add to prepared baking dish. Repeat with remaining tortillas.
Spread any remaining enchilada sauce over the top of the tortillas and sprinkle top with remaining cheese.
Bake, uncovered, for 20-23 minutes, until hot and bubbly and cheese is completely melted.
Sprinkle top with chopped cilantro. Serve garnished with a little sour cream, cilantro, pico de gallo, diced avocado, etc.